Assembly group of a vehicle seat comprising

ABSTRACT

An assembly group of a vehicle seat, comprises a lower guide rail attachable to a vehicle floor and an upper guide rail coupled to the lower guide rail and movable with respect to the lower guide rail along a longitudinal axis, the upper guide rail comprising a top wall and a pair of side walls connected by the top wall. A link arm is pivotably connectable to the upper guide rail for coupling a frame assembly to the upper guide rail. A first fastener for pivotably coupling the link arm to the upper guide rail is disposed between the pair of side walls and being at least partially positioned below a top surface of the top wall.

TECHNICAL FIELD

The instant invention relates to an assembly group of a vehicle seat.The instant invention in particular relates to an assembly group of avehicle seat comprising a lower guide rail attachable to a vehicle floorand an upper guide rail coupled to the lower guide rail and movable withrespect to the lower guide rail along a longitudinal axis, the upperguide rail and the lower guide rail being part of a length adjustmentdevice for adjusting a length position of the vehicle seat with respectto a vehicle floor.

BACKGROUND

For a vehicle seat, in particular a front seat in a vehicle, it isdesirable to be able to adjust the height of a seat part in order toallow adapting the vehicle seat for providing a comfortable seating fora passenger. For this, typically one or multiple link arms are pivotablyconnected to an upper guide rail on either side of a vehicle seat, suchthat, by pivoting the one or the multiple link arms, a frame assemblyconnected to the upper guide rail by means of the one or the multiplelink arms is adjusted in its height position with respect to the upperguide rail.

Herein, the lowest position of the frame assembly with respect to theupper guide rail, the so-called “low block height”, is generally definedby the connection of the one or the multiple link arms to the upperguide rail. The connection of a link arm to the upper guide rail inparticular defines a pivot axis about which the link arm is pivotablewith respect to the upper guide rail, the position of the pivot axiswith respect to the upper guide rail constraining the ability to lowerthe low block height of the vehicle seat.

Different arrangements of a fastener element on an upper guide rail areknown for example from DE 10 2010 042 008 A1, DE 10 2010 042 285 A1, andDE 10 2010 051 955 A1.

SUMMARY OF THE INVENTION

It is an object to provide an assembly group of a vehicle seat whichallows to lower the low block height, the low block height defining thelowest position to which a frame assembly of a vehicle seat can beapproached towards the upper guide rail by pivoting a link arm withrespect to the upper guide rail.

In one aspect, an assembly group of a vehicle seat is provided, theassembly group comprising: a lower guide rail attachable to a vehiclefloor; an upper guide rail coupled to the lower guide rail and movablewith respect to the lower guide rail along a longitudinal axis, theupper guide rail comprising a top wall and a pair of side wallsconnected by the top wall; a link arm pivotably connectable to the upperguide rail for coupling a frame assembly to the upper guide rail; and afirst fastener for pivotably coupling the link arm to the upper guiderail, the first fastener being disposed between the pair of side wallsand being at least partially positioned below a top surface of the topwall.

According to one aspect, the first fastener serves to pivotably couplethe link arm to the upper guide rail. The first fastener herein isdisposed between the pair of side walls and extends from one side wallto another, the first fastener being at least partially positionedbeneath a top surface of the top wall, the top surface being located atan upper side of the top wall opposite the side walls extending from thetop wall towards the lower guide rail. Because the first fastener atleast partially is positioned below the top surface of the top wall, theposition of the pivot axis provided by the first fastener can be loweredwith respect to the top wall of the upper guide rail, hence reducingconstraints on lowering the lower block height.

In one embodiment, a second fastener is connectable to the firstfastener for pivotably coupling the link arm to the upper guide rail.The first fastener herein may have the shape of a threaded sleevecomprising a threaded opening for receiving the second fastener, whichin this case is shaped as a threaded stud comprising a threaded shaft.In another embodiment, the first fastener is shaped as a threaded studcomprising a threaded shaft, a second fastener in the shape of athreaded sleeve being screw-connectable to the first fastener.

The first fastener and the second fastener together serve to provide abearing for the link arm to pivotably connect the link arm to the upperguide rail. For this, one of the first fastener and the second fastenermay comprise a bearing section on which the link arm may be receivedsuch that the link arm is pivotable with respect to the first fastenerand the second fastener. By pivoting the link arm with respect to theupper guide rail the height position of the frame assembly with respectto the upper guide rail can be adjusted such that the frame assembly canfor example be approached towards the upper guide rail in order to lowera seat height of the vehicle seat.

In another aspect, the upper guide rail comprises an aperture forreceiving the first fastener.

In one embodiment, the aperture may be formed in the top wall such thatit reaches into both side walls, the aperture providing for a recess inthe shape of a notch (cutout) in which the first fastener may bedisposed such that the first fastener at least partially reaches intothe recess and hence is at least partially positioned below the topsurface of the top wall.

In another embodiment, each side wall of the pair of side wallscomprises a bore, the bores of the side walls together forming anaperture for receiving the first fastener. The bores of the side wallsin particular may be aligned with respect to each other along atransverse direction pointing transverse to the longitudinal axis suchthat the first fastener may be inserted into the bores to extend inbetween the side walls of the upper guide rail.

In one aspect, the first fastener, for example in the shape of athreaded sleeve or a threaded stud, extends along a direction transverseto the longitudinal axis from a first side wall of the pair of sidewalls to a second side wall of the pair of side walls. The firstfastener hence extends transversely across the upper guide rail from oneside wall to the other side wall, thus allowing for a strong connectionof the fast first fastener to the upper guide rail.

In one embodiment, the first fastener is connected to the upper guiderail by means of a weld joint. The first fastener hence may be directlyconnected to the upper guide rail, for example to the top wall of theupper guide rail or to one or both of the side walls of the upper guiderail, by welding, for example by laser welding or by MIG or MAG welding.For example, if an aperture is formed in the top wall of the upper guiderail, the first fastener may be connected by welding to edges of theaperture formed in the top wall. If the aperture is formed by bores inthe side walls, the first fastener may be connected to the side walls byweld joints extending about each bore.

In another embodiment, an attachment bracket may be provided serving toconnect the first fastener to the upper guide rail. Herein, theattachment bracket may for example be connected to the top wall of theupper guide rail, wherein the first fastener is connected to theattachment bracket by means of a weld joint, for example by laserwelding or by MIG or MAG welding. In this embodiment, the first fasteneris for example not connected directly to the upper guide rail, but isconnected to the attachment bracket and via the attachment bracket tothe upper guide rail. A weld joint hence is formed in between the firstfastener and the attachment bracket, but not in between the firstfastener and the upper guide rail, allowing for example to pre-assembleand deliver a sub assembly comprising an attachment bracket and a firstfastener connected to the attachment bracket.

In one embodiment, the attachment bracket is connected to the upperguide rail, in particular the top wall of the upper guide rail, bywelding. The attachment bracket herein may be formed such that itbridges, when it is connected to the top wall of the upper guide rail,an aperture formed in the top wall for receiving the first fastener, theattachment bracket hence reaching over the aperture along thelongitudinal axis and hence increasing the strength of the upper guiderail in the neighborhood of the aperture formed in the top wall.

In one embodiment, the attachment bracket comprises a middle section andat least one flange section, wherein the middle section confines areception opening for receiving the first fastener. The middle sectionmay have a generally rectangular (C) shape or a rounded shape and servesto receive the first fastener therein. The first fastener herein may beconnected to the middle portion by means of welding, for example bylaser welding or MIG or MAG welding.

The at least one flange section may for example be flatly placed on thetop wall of the upper guide rail. The at least one flange section mayfor example be connected to the top wall by welding, for example laserwelding or MIG or MAG welding. The at least one flange section forms alap joint with the top wall, wherein one or multiple projections may beprovided on the at least one flange section for engaging with anassociated, complementary opening in the top wall for establishing aparticularly strong welded connection in between the attachment bracketand the top wall of the upper guide rail.

In one embodiment, the attachment bracket comprises two flange sections,one flange section being placed at each side of the middle portion. Eachflange section flatly abuts the top wall of the upper guide rail,wherein the attachment bracket is connected to the upper guide rail bywelding each flange section to the top wall.

In another aspect, in a preassembly state in which the first fastener isseparate from the attachment bracket, the first fastener may bereceivable within the reception opening confined by the middle portionof the attachment bracket at different height positions when viewedalong a vertical direction perpendicular to the top wall of the upperguide rail. Prior to fixedly connecting the first fastener to theattachment bracket the first fastener may be brought into a suitableposition with respect to the attachment bracket, the first fastener inparticular being placeable on the attachment bracket such that the firstfastener may assume different height positions with respect to themiddle portion of the attachment bracket. This allows to adjust theheight position of the first fastener with respect to the attachmentbracket and hence with respect to the top wall of the upper guide rail,such that a lower block height may be adapted as desired by suitablyplacing the first fastener on the attachment bracket and connecting thefirst fastener to the attachment bracket.

According to one aspect, a sub-assembly comprises: a first fastener forpivotably coupling a link arm to an upper guide rail of a vehicle seat,the first fastener being configured to be disposed between a pair ofside walls of the upper guide rail and to be at least partiallypositioned below a top surface of a top wall of the upper guide rail;and an attachment bracket configured to be connected to the top wall ofthe upper guide rail, wherein the first fastener is connected to theattachment bracket by means of a weld joint.

A sub-assembly of this kind may be manufactured and delivered to acustomer in a state in which it is not connected to the upper guiderail. The sub-assembly is configured to be placed on an upper guide railsuch that the first fastener is for example received in an apertureformed in the top wall of the upper guide rail and hence is positionedat least partially below the top surface of the top wall of the upperguide rail.

In one embodiment, said attachment bracket of the sub-assembly comprisesa middle section and at least one flange section, wherein the middlesection confines a reception opening for receiving the first fastener.The middle section may have a generally rectangular (C) shape or roundedshape and serves to receive the first fastener therein. The firstfastener herein may be connected to the middle portion by means ofwelding, for example by laser welding or MIG or MAG welding.

The at least one flange section may for example be flatly placed on thetop wall of the upper guide rail. The at least one flange section mayfor example be connected to the top wall by welding, for example laserwelding or MIG or MAG welding. The at least one flange section forms alap joint with the top wall, wherein one or multiple projections may beprovided on the at least one flange section for engaging with anassociated, complementary opening in the top wall for establishing aparticularly strong welded connection in between the attachment bracketand the top wall of the upper guide rail.

In one embodiment, the attachment bracket comprises two flange sections,one flange section being placed at each side of the middle portion. Eachflange section flatly abuts the top wall of the upper guide rail,wherein the attachment bracket is connected to the upper guide rail bywelding each flange section to the top wall.

In one embodiment, in a preassembly state of the sub-assembly in whichthe first fastener is separate from the attachment bracket, the firstfastener may be receivable within the reception opening confined by themiddle portion of the attachment bracket at different height positionswhen viewed along a vertical direction perpendicular to the top wall ofthe upper guide rail. Prior to fixedly connecting the first fastener tothe attachment bracket the first fastener may be brought into a suitableposition with respect to the attachment bracket, the first fastener inparticular being placeable on the attachment bracket such that the firstfastener may assume different height positions with respect to themiddle portion of the attachment bracket.

BRIEF DESCRIPTION OF THE DRAWINGS

The various features and advantages of the present invention may be morereadily understood with reference to the following detailed descriptionand the embodiments shown in the drawings. Herein,

FIG. 1 shows a vehicle seat;

FIG. 2 shows an embodiment of an upper guide rail and two link armspivotably connected to the upper guide rail;

FIG. 3 shows an embodiment of an upper guide rail with fastener elementsconnected to the upper guide rail by means of an attachment bracket;

FIG. 4 shows a side view of the embodiment of FIG. 3;

FIG. 5 shows a top view of the embodiment of FIG. 3;

FIG. 6 shows another embodiment of an upper guide rail and fastenerelements to be connected directly to the upper guide rail;

FIG. 7 shows a side view of an upper guide rail;

FIG. 8 shows a view of another embodiment of an upper guide rail withfastener elements connected to the upper guide rail;

FIG. 9 shows a bottom view of the embodiment of FIG. 8;

FIG. 10 shows a view of another embodiment of an upper guide rail withfastener elements connected to the upper guide rail;

FIG. 11 shows a view of an embodiment of an attachment bracket forfixing a fastener element to an upper guide rail;

FIG. 12 shows a side view of the attachment bracket according to FIG.11;

FIG. 13 shows another embodiment of an attachment bracket;

FIG. 14 shows yet another embodiment of an attachment bracket;

FIG. 15 shows an embodiment of an attachment bracket in connection witha fastener element, at a first height position;

FIG. 16 shows a perspective view of the arrangement of FIG. 15;

FIG. 17 shows the attachment bracket and the fastener element, atanother, second height position of the fastener element with respect tothe attachment bracket;

FIG. 18 shows a perspective view of the arrangement of FIG. 17;

FIG. 19 shows another embodiment of an attachment bracket in connectionwith a fastener element;

FIG. 20 shows yet another embodiment of an attachment bracket inconnection with a fastener element;

FIG. 21 shows an embodiment of a fastener element to be connected to anupper guide rail;

FIG. 22 shows another embodiment of a fastener element to be connectedto an upper guide rail;

FIG. 23 shows yet another embodiment of a fastener element to beconnected to an upper guide rail;

FIG. 24 shows the fastener element of FIG. 23 in association withanother, second fastener element;

FIG. 25 shows the fastener elements of FIG. 24, in a connected state.

DETAILED DESCRIPTION

Subsequently, embodiments of the invention shall be described in detailwith reference to the drawings. In the drawings, like reference numeralsdesignate like structural elements.

It is to be noted that the embodiments are not limiting for theinvention, but merely represent illustrative examples.

FIG. 1 shows, in a schematic view, a vehicle seat 1 which comprises aseat part 10 and a backrest part 11 which is connected to the seat part10 and is generally adaptable in its inclination with respect to theseat part 10.

The seat part 10 comprises a frame assembly 100 which, by means of linkarms 120, 121 of an height adjustment mechanism 12, is connected to anupper guide rail 2 coupled to a lower guide rail 3 and forming a part ofa length adjustment mechanism 13. Via the length adjustment mechanism 13the vehicle seat 1 is arranged on a vehicle floor 14.

A vehicle seat 1 generally comprises two pairs of link arms 120, 121 andtwo pairs of guide rails 2, 3, one on each side of the vehicle seat 1.

The link arms 120, 121 can be pivoted with respect to both the frameassembly 100 of the seat part 10 and the associated upper guide rail 2in order to adjust the height position of the seat part of 10 withrespect to the vehicle floor 14. In this way, the seat part 10 inparticular can be lowered to assume a lower height position, and can beraised in order to assume an elevated height position, such that theheight of the seat part 10 can be adjusted according to userpreferences.

The lowest position of the seat part 10 with respect to the upper guiderail 2 generally is constrained by the connection of the link arms 120,121 to the upper guide rail 2, the height of the seat part 10 at itslowest position being referred to as “low block height”. There in thisrespect is a general desire to reduce constraints and to be able tolower the low block height.

Referring now to FIG. 2, link arms 120, 121 are pivotably connected toan upper guide rail 2 such that the link arms 120, 121 can pivot withrespect to the upper guide rail 2 about pivot axes P2, P4. At pivot axesP1, P3 the link arms 120, 121 are connected to the frame assembly 100 ofthe associated seat part 10, such that by pivoting the link arms 120,121 with respect to the upper guide rail 2 the height position of theseat part 10 with respect to the upper guide rail 2 can be adjusted.

As visible from FIG. 2, the upper guide rail 2 comprises a top wall 20and side walls 21, 22 which are connected by the top wall 20 andtogether with the top wall 20 form a generally U-shaped rail. The upperguide rail 2 is coupled to an associated lower guide rail 3 (asschematically shown in FIG. 1) and is slidably guided, along alongitudinal axis L, on the lower guide rail 3 in that lower edges 210,220 of the side walls 21, 22 engage with the lower guide rail 3 and areslidably mounted within the lower guide rail 3 for example via ballbearings or the like.

Referring now to FIGS. 3 to 5, in an embodiment of an upper guide rail 2fastener elements 41 of sub-assemblies 4 are mounted on the upper guiderail 2 in order to provide for a coupling of the link arms 120, 121 tothe upper guide rail 2. Each sub-assembly 4 comprises an attachmentbracket 40 having a middle section 400 and flange sections 401, 402laterally extending from the middle section 400 and flatly abutting thetop wall 20 of the upper guide rail 2. Within the middle section 400, afastener element 41 in the shape of a threaded sleeve is received, thefastener element 41 being fastened to the middle section 400 by means ofweld joints 43 on both sides of the fastener element 41, as this isvisible from FIG. 4.

The weld joints 43 may for example be formed using laser welding or MIGor MAG welding.

Each fastener 41 hence is fixedly connected to an associated attachmentbracket 40 of a sub-assembly 4. The attachment bracket 40 in turn isconnected to the top wall 20 of the upper guide rail 2 via the flangesections 401, 402, for example by forming a weld connection in betweenthe flange sections 401, 402 and the top wall 20 of the upper guide rail2 using laser welding or MIG or MAG welding.

The flange sections 401, 402 may flatly abut the top wall 20 at a topface 207 facing outwards such that the flange sections 401, 402 form aweld joint with the top wall 20. A weld joint in between the flangesections 401, 402 may be formed directly in between the flange sections401, 402 and the top wall 20, wherein in addition projections 407, asschematically illustrated in FIG. 5, may be formed on the flangesections 401, 402 to engage with corresponding openings in the top wall20 of the upper guide rail 2 (or vice versa) to form weld joints on suchprojections 407.

As visible from FIG. 3, FIG. 4 and in addition from FIG. 7, the upperguide rail 2 comprises apertures 200, 201 formed at axially displacedlocations on the top wall 20, the apertures 200, 201 extending into bothside walls 21, 22. By means of the apertures 200, 201 recesses areformed on the upper guide rail 2, which are configured to receive thefastener 41 of an associated sub-assembly 4, as visible from FIGS. 3 and4.

By providing the apertures 200, 201 on the upper guide rail 2, thefasteners 41 of the sub-assemblies 4 may be received and positioned onthe upper guide rail 2 such that the fasteners 41 partially are disposedbeneath the top face 207 of the top wall 20, as it in particular isvisible from FIG. 4. As the fasteners 41 define the pivot axes P2, P4for coupling the link arms 120, 121 to the upper guide rail 2, in thisway the height position of the pivot axes P2, P4 can be lowered withrespect to the top face 207 of the top wall 20, such that a coupling inbetween the link arms 120, 121 and the upper guide rail 2 may beestablished at a lower height position. This allows to reduceconstraints on the low block height and potentially allows to define alower limit for the low block height.

Each fastener 41 extends transversely to the longitudinal axis L along atransverse direction Q and herein extends in between the two side walls21, 22 such that it fully extends from one side wall 21 to the otherside wall 22.

As visible from FIGS. 3 and 4, the attachment bracket 40 of eachsub-assembly 4 extends across the associated aperture 200, 201 formed onthe upper guide rail 2, the attachment bracket 40 hence bridging theassociated aperture 220, 201 and hence increasing the strength of theupper guide rail 2 in the vicinity of the associated aperture 200, 201.

In the embodiment of FIGS. 3 to 5 each fastener 41 is formed as athreaded sleeved, the fastener 41 comprising a threaded opening 410 intowhich another, second fastener 42 formed as a threaded stud may bescrewed. The fastener 42 in particular comprises a threaded shaft 420which may be screwed into the threaded opening 410 of the fastener 41.The fastener 42 furthermore comprises a cylindrical bearing section 421axially confined by a head section 422, the bearing section 421 beingconfigured to receive a link arm 120, 121 for pivotably mounting thelink arm 120, 121 on the upper guide rail 2.

In another embodiment shown in FIG. 6 fasteners 41 may be directlywelded, by means of weld joints 43 formed on both sides of therespective fastener 41, to the upper guide rail 2, without using anattachment bracket 40. The weld joints 43 are formed by weld lines inbetween the fastener 41 and a corresponding edge 202, 203 of theassociated aperture 200, 201 formed on the top wall 20 of the upperguide rail 2, such that the fastener 41 is received in an associatedaperture 200, 201 and is directly connected to the upper guide rail 2 bywelding.

In yet another embodiment shown in FIGS. 8 and 9, apertures 200, 201 inthe shape of bores in both side walls 21, 22 are formed on the upperguide rail 2, fasteners 41 being placed within the apertures 200, 201such that each fastener 41 is received in the bores on the side walls21, 22 and extends from one side wall 21 to the other side wall 22. Eachfastener 41 herein may be connected to the upper guide rail 2 by meansof weld joints 43 having a circular shape and being formed tocircumferentially extend about each bore, as visible from FIG. 8.

When comparing the upper guide rail 2 according to the embodiment ofFIG. 8 for example to the upper guide rail 2 as shown in FIG. 3, it isvisible that the top wall 20 is elevated in the embodiment of FIG. 8 incomparison to the embodiment of FIG. 3. This is to fully receive thefasteners 41 beneath the top wall 20, the fasteners 41 extending inbetween the side walls 21, 22 across an inner space of the upper guiderail 2 beneath the top wall 20.

In another embodiment shown in FIG. 10, the top wall 20 is onlypartially elevated at elevated portions 205, 206, a middle portion 204of the top wall 20 being recessed with respect to the elevated portions205, 206. The fastener 41 herein are received in apertures 200, 201formed by bores in the side walls 21, 22 in the region of the elevatedportion 205, 206.

When using an attachment bracket 40 to connect a fastener 41 to theupper guide rail 2, as in the embodiment of FIGS. 3 to 5, attachmentbrackets 40 of different shape and constitution may be used.

In one embodiment as shown in FIGS. 11 and 12, an attachment bracket 40may have a general C-shape, flange sections 401, 402 extending laterallyfrom a middle section 400, the flange sections 401, 402 being formed toform a lap joint with the top wall 20 of an upper guide rail 2 and beingconfigured to establish a welding connection in between the attachmentbracket 40 and the associated top wall 20. The middle section 400 formsa reception space 403 in which an associated fastener 41 may bereceived, as this shall be explained further below with reference toFIGS. 15 to 18.

The flange sections 401, 402 of the attachment bracket 40 may be adaptedto provide a lap joint with the top wall 20 of the associated upperguide rail 2, the lap joint being fixated by welding in order to exhibita desired strength and being adapted to the shape of the top wall 20. Inparticular, the axial length of the flange sections 401, 402 (measuredalong the longitudinal axis L) may be adapted, as visible from FIG. 12and FIG. 13, according to a desired overlap and a desired area to form aweld connection, wherein it also is conceivable to form the flangesections 401, 402 with different axial lengths, as this is visible inFIG. 14.

As visible from FIGS. 15 to 18, a fastener 41 may be received within thereception space 403 of the middle section 400 at different heightpositions, measured along a vertical direction Z perpendicular to thetop face 207 of the top wall 20 of an associated upper guide rail 2. Bypositioning the fastener 41 at a suitable height position within thereception space 403 the pivot axis P2 of a link arm 120, 121 may bedefined with respect to the upper guide rail 2 in a variable, adjustablemanner, wherein after positioning the fastener 41 within the receptionspace 403 the fastener 41 is connected to the middle section 400 of theattachment bracket 40 by means of weld joints 43 (in the shape of weldlines extending transversely along the transverse direction Q).

FIGS. 15 and 16 illustrate a placement of a fastener 41 at acomparatively low height position with respect to the attachment bracket40, whereas FIGS. 17 and 18 shows an embodiment of a fastener 41 placedwithin the reception space 403 at an elevated height position withrespect to the attachment bracket 40.

The weld joint 43, in FIGS. 15 to 18, may in particular be formed by MIGor MAG welding.

A sub-assembly 4 as shown in FIGS. 15 to 18 may be manufactured toprovide a pre-assembly group, which may then be attached to and fastenedon an associated upper guide rail 2.

Other shapes of attachment brackets 40 are conceivable.

For example, as shown in FIG. 19, the middle section 400 of anattachment bracket 40 may have a rounded shape for receiving a fastenerelement 41, the curvature of the middle section 400 being adapted to thecurvature of the fastener 41. In this embodiment, weld joints 43 in theshape of weld lines extending transverse along the transverse directionQ may be formed in between the fastener 41 and the attachment bracket 40to fix the fastener 41 to the attachment bracket 40.

In another embodiment shown in FIG. 20, a front face 404 comprising anopening 405 for receiving the fastener 41 is connected by connectingportions 406 to flange sections 401, 402 of an attachment bracket 40. Inthis embodiment, for example a weld joint 43 curved about the transversedirection Q may be formed to connect the fastener 41 to the middlesection 400 of the attachment bracket 40.

A fastener 41 to be connected to an associated upper guide rail 2 mayhave different forms and functions, as shown in FIGS. 21 to 23. Thefastener 41 may in particular be shaped as a threaded sleeve having abody portion 411 and a threaded opening 410 formed within the bodyportion 411, as shown in FIGS. 21 and 22, wherein in addition a bearingface 412 may be formed on the body portion 411 to extend radially beyondthe body portion 411, as shown in FIG. 22. The bearing face 412 providesan abutment face for axially abutting an associated link arm 120, 121.

In another embodiment shown in FIG. 23, the fastener 41 is shaped as athreaded stud comprising a body portion 411 to be fastened to the upperguide rail 2, the fastener 41 furthermore comprising a threaded shaft414, a cylindrical section 413 and a bearing face 412. As shown in FIGS.24 and 25, another, second fastener 42 in the shape of a nut having athreaded opening 423 may be placed on the threaded shaft 414, wherein inaddition a bearing element 44 is to be placed on the cylindrical section413 of the fastener 41 in order to form a bearing for an associated linkarm 120, 121. The bearing element 44 comprises a bearing section 440axially confined by a bearing face 441, an opening 442 extending throughthe bearing element 44 such that the bearing element 44 may be placed onthe cylindrical section 413 of the fastener 41, as visible in FIG. 25.By screwing the fastener 42 onto the threaded shaft 414 of the fastener41, the bearing element 44 can axially be fixed on the fastener 41, suchthat a link arm 120, 121 received on the bearing section 440 ispivotably coupled to an upper guide rail 2.

The embodiments described herein are not limiting for the invention asset forth in the claims, but merely provide illustrative examples. Theinvention can be carried out in an entirely different manner in entirelydifferent embodiments.

REFERENCE NUMERALS

-   1 Vehicle seat-   10 Seat part-   100 Frame assembly-   11 Backrest part-   12 Height adjustment mechanism-   120, 121 Link arm-   13 Length adjustment mechanism-   14 Vehicle floor-   2 Upper guide rail-   20 Top wall-   200, 201 Aperture-   202, 203 Edge-   204 Middle portion-   205, 206 Elevated portion-   207 Top surface-   21, 22 Side walls-   210, 220 Lower edge-   3 Lower guide rail-   4 Sub-assembly-   40 Attachment bracket-   400 Middle section-   401, 402 Flange section-   403 Reception space-   404 Front face-   405 Opening-   406 Connecting portion-   407 Projection-   41 First fastener-   410 Threaded opening-   411 Body portion-   412 Bearing face-   413 Cylindrical section-   414 Threaded shaft-   42 Second fastener-   420 Threaded shaft-   421 Bearing section-   422 Head section-   423 Threaded opening-   43 Weld joint-   44 Bearing element-   440 Bearing section-   441 Bearing face-   442 Opening-   L Longitudinal axis-   P1-P4 Pivot axis-   Q Transverse direction-   Z Vertical direction

1. Assembly group of a vehicle seat, comprising: a lower guide railattachable to a vehicle floor; an upper guide rail coupled to the lowerguide rail and movable with respect to the lower guide rail along alongitudinal axis, the upper guide rail comprising a top wall and a pairof side walls connected by the top wall; a link arm pivotablyconnectable to the upper guide rail for coupling a frame assembly to theupper guide rail; and a first fastener for pivotably coupling the linkarm to the upper guide rail, the first fastener being disposed betweenthe pair of side walls and being at least partially positioned below atop surface of the top wall.
 2. Assembly group according to claim 1,further comprising a second fastener connectable to the first fastenerfor pivotably coupling the link arm to the upper guide rail.
 3. Assemblygroup according to claim 2, wherein one of the first fastener and thesecond fastener comprises a threaded opening and the other of the firstfastener and the second fastener comprises a threaded shaft to bescrewed into said threaded opening for connecting the first fastener andthe second fastener to each other.
 4. Assembly group according to claim1, wherein the upper guide rail comprises an aperture for receiving thefirst fastener.
 5. Assembly group according to claim 4, wherein theaperture is formed in the top wall and in both side walls of the pair ofside walls.
 6. Assembly group according to claim 4, wherein each sidewall of the pair of side walls comprises a bore, the bores of the sidewalls together forming said aperture for receiving the first fastener.7. Assembly group according to claim 1, wherein the first fastenerextends, along a direction transverse to the longitudinal axis, from afirst side wall of the pair of side walls to a second side wall of thepair of side walls.
 8. Assembly group according to claim 1, wherein thefirst fastener is connected to the upper guide rail by means of a weldjoint.
 9. Assembly group according to claim 1, further comprising anattachment bracket connected to the top wall of the upper guide rail,wherein the first fastener is connected to the attachment bracket bymeans of a weld joint.
 10. Assembly group according to claim 9, whereinthe attachment bracket bridges, along the longitudinal axis, an apertureformed in the top wall for receiving the first fastener.
 11. Assemblygroup according to claim 9, wherein the attachment bracket comprises amiddle section and at least one flange section, wherein the middlesection confines a reception opening for receiving the first fastenerand the at least one flange section is flatly placed on the top wall ofthe upper guide rail.
 12. Assembly group according to claim 11, whereinthe at least one flange section is connected to the top wall of theupper guide rail by welding.
 13. Assembly group according to claim 11,wherein the first fastener is connected to the middle portion by meansof at least one weld joint.
 14. Assembly group according to claim 11,wherein, in a pre-assembly state in which the first fastener is separatefrom the attachment bracket, the first fastener is receivable within thereception opening confined by the middle portion at different heightpositions when viewed along a vertical direction perpendicular to thetop wall of the upper guide rail.
 15. Sub-assembly, comprising: a firstfastener for pivotably coupling a link arm to an upper guide rail of avehicle seat, the first fastener being configured to be disposed betweena pair of side walls of the upper guide rail and to be at leastpartially positioned below a top surface of a top wall of the upperguide rail; and an attachment bracket configured to be connected to thetop wall of the upper guide rail, wherein the first fastener isconnected to the attachment bracket by means of a weld joint. 16.Sub-assembly according to claim 15, wherein the attachment bracketcomprises a middle section and at least one flange section, wherein themiddle section confines a reception opening for receiving the firstfastener and the at least one flange section is configured to be flatlyplaced on the top wall of the upper guide rail.
 17. Sub-assemblyaccording to claim 16, wherein the at least one flange section isconfigured to be connected to the top wall of the upper guide rail bywelding.
 18. Sub-assembly according to claim 16, wherein the firstfastener is connected to the middle portion by means of at least oneweld joint.
 19. Sub-assembly according to claim 16, wherein, in apre-assembly state in which the first fastener is separate from theattachment bracket, the first fastener is receivable within thereception opening confined by the middle portion at different heightpositions when viewed along a vertical direction perpendicular to thetop wall of the upper guide rail.